OLAP tool for comparing time-based data

14th May 2008

Proposed By

Pimolmas Ponchaisakuldee 104915

Advisor Dr. Paul Janecek

Contents

Introduction1

Implementation2

Experimental Evaluation3

Conclusion4

What is Data warehouse & OLAP

Data warehouse a very large database with special characteristic Data for analyzing

OLAP tool (On-Line Analytical Processing) A tool on top of data warehouse For data exploring and analyzing

3

OLAP tool Problems

Cube navigationData presentation

4

OLAP tool Problems

Cube navigation Problems of window-explorer-like tree browser

• Lose in tree topology

• Need several clicks Requirements

• Overall topology

• Multiple focuses and topology at the same time Solutions

• DOITree browser (better topology representation, multiple focuses, and go more than one level of hierarchy per click)

• DOITree VS Window-Explorer-like browser

5

OLAP tool Problems

Data presentation Tasks

• Trend finding over time• Trend comparison between 2 period of time

Problems• Pivot table: hard to do the analysis task• Existing graph: complex, hard to focus• Polaris table

– does not support hierarchy exploring of data– Problem of composition for comparison task

Solution• Focus on demand graph = graph matrix + overlaid graph

6

Objectives

To build OLAP tool To evaluate effectiveness of DOITree

visualization for OLAP-specific navigation compare to Window-Explorer-like visualization

To evaluate visual tools for time-based comparison task• Graph matrix• Overlaid graph

7

Focus on demand graph

Contents

Introduction1

Implementation2

Experimental Evaluation3

Conclusion4

Implementation

Java to modified JRubik

9

Cube Navigator

Pivot table presentation

Graph matrix presentation

Overlaid Graph

Items ListHierarchy List

Query Reset

Hierarchies on column

Items ListHierarchy List

Items on column Hierarchies on row Items on row

Design when measure is on column

10

Design when measure is on row

11

Contents

Introduction1

Implementation2

Experimental Evaluation3

Conclusion4

Evaluation 1: (WD) VS (DOI)

Window-Explorer Like browser (WD) of JRubik

DOI tree browser (DOI) of the modified JRubik

13

14

Evaluation 2: (GE) VS (FOCUS)

Overlaid Graph

General graph (GE)Focus on

demand graph (FOCUS)Graph Matrix

+VS

Experiment design

Participants will be trained to use the 2 tools The modified JRubik = (DOI) and (FOCUS) JRubik = (WD) and (GE)

Experiment design with counterbalancing order

15

Participants First Tool Second Tool Data

Student01 to Student10

The modified JRubik JRubik Foodmart

Student11 to Student20

JRubik The modified JRubik Foodmart

Staff1 and 2 The modified JRubik JRubik AIT admission

Staff3 and 4 JRubik The modified JRubik AIT admission

First Evaluation: (WD) VS (DOI)

Tasks for browser comparison Only browsers (one attribute) Appendix C page 83

• Task1 - First Node Finding • Task2 - First time Node Finding• Task3 - Subtree Revisiting• Task4 - Node Revisiting

The browsers as query tool (many attributes) Appendix D page 84

• Task1 - First time Node Finding• Task2 - Subtree Revisiting• Task3 - Node Revisiting

16

WD

DOI

WD

DOI

Second Evaluation: (GE) VS (FOCUS)

Tasks for graph comparison Simple Analysis

• Trend finding, Trend comparing Complex Analysis

• Trend comparing

17

Second Experiment: (G) VS (F)

Simple Analysis

Complex Analysis

18

Experiment Result

Browser comparison result: browsers only Subtree revisiting – users can leave subtrees open

22

First time node

finding

First node

finding

Subtree revisiting

Node revisiting

First time node

finding

First node

finding

Subtree revisiting

Node revisiting

Sig. DOI

Sig. WD

WD

DOI

Sig. WD

Sig. DOI

DOI

WD

Experiment Result

Browser comparison result: browsers only Finding for DOITree

• Advantage– More information help users to recover from mistake

• Disadvantage– More information can distract users to go wrong path

23

Experiment ResultBrowser comparison result: browser as a query

tool

24

First node finding

First node finding

Subtree revisitingSubtree revisiting

Node revisiting

Node revisiting

WD

DOI

Sig. DOI

Sig. WD

WD

DOI

Experiment ResultBrowser comparison result: browser as a query tool

(DOI) always take less clicks Go more than one level per click using (DOI) Users shrink subtree before finding new node using

(WE)

25

First node finding

First node finding

Subtree revisitingSubtree revisiting

Node revisiting

Node revisiting

25

WD

DOI

Sig. DOI

Sig. WD

WD

DOI

Experiment Result

Graph comparison result

27

FOCUSGE

Sig. FOCUS

Sig. GE

GE

FOCUS

Discussion

Personal Evaluation

32

Tasks Subtasks JPivot FreeAnalysis

JRubik Modified JRubik

T4: Analyzing visualization presentation

T4.1: How easy to read text of each graph + +++ + +++T4.2: How easy to read exact value in graph + + +++ ++++

T4.3: How easy to find trend of data + ++ + ++++T4.4: How easy to compare trend of data ++ + ++ ++++

Contents

Introduction1

Implementation2

Experimental Evaluation3

Conclusion4

Conclusion Problems

Cube navigation, Data Presentation Objectives

to evaluate effectiveness of (DOI) compare to (WD) to evaluate the focus on demand graph for time-based data analysis tasks

Browser comparison result:

34

Tasks The better Sig. Note

Browsers only

First time node finding (DOI) -

First node finding = -

Subtree revisiting (WE) Leave subtree open

Node revisiting (DOI) Some users shrink subtree

Browsers as query tool

First node finding (DOI) At middle depth (very deep has animation)

Subtree revisiting (DOI) When subtree expanded

Node revisiting (DOI) When subtree expanded

WD

DOI

Conclusion Graph comparison result:

Implications Browser comparison:

• Browser only: (DOI) is better for long term usage, (WE) is good for revisiting tasks

• Query tool: DOITree is better for unknown data and suitable for the analyzers who are always analyze unknown data

Graph comparison:• separated graph in graph matrix can eliminate complexity• Users can focus what they want• line graph is a suitable presentation when time is on X axis

35

Criteria The better Sig. Note

Pair-sample T-Test

Simple Analysis Tasks (FOCUS) -

Complex Analysis Tasks (FOCUS) -

FOCUSGE